The present invention relates to an ice making apparatus and method particularly adapted for use in conjunction with automatic beverage dispensers or other devices requiring frequent dispensing of small quantities of ice. It is also particularly adapted for ice makers utilizing small hoppers relative to the total amount of ice dispensed which typically make ice continuously during an ice making cycle.
Automatic ice makers are well known in the art and are available in many forms and typically have hoppers for temporary storage of manufactured ice. Beverage dispensers of the coin operated type, dispense both ice and beverage when the requisite amount of money is provided and a beverage selection is made. A cup is automatically dispensed, ice is fed to the cup and then beverage is dispensed to the cup. Such vending machines are commonly used in cafeterias and break rooms. A typical vending machine is a model 328 from Crane National Vendors. Many ice makers have control systems to improve their operation and/or efficiency. Typically, the ice maker will cease making ice when the ice bin is full and commence ice making when the ice level in the hopper reaches a low level. Such a control system does not readily adapt itself to ice makers having small hoppers, for example, a four pound capacity hopper, relative to the amount of ice dispensed, like ice makers associated with coin operated beverage dispensers. Nor is such a control system well adapted for ice makers where the amount of dispensed ice varies, sometimes significantly, throughout a day or by day of week. Ice makers using such control systems can produce poor quality ice and present operational problems such as ice clumping. When ice is retained in a hopper for an extended period, it tends to clump together forming large blocks of ice that cannot be dispensed requiring its removal sometimes leaving an empty or nearly empty hopper and thereby potentially unable to meet demand. Also, the ice feeder in the hopper may break the clumped ice and unclumped ice degrading its quality by leaving pieces that are too large or small and may also warm the ice.
Clumping can occur at night, over weekends or during other periods when the rate of ice dispensing is reduced. Generally, ice makers associated with vending machines function such that ice in the hopper is not being moved or mixed unless dispensing is occurring or ice is being made which lack of movement can also encourage clumping. Clumping can be due to the temperature in the hopper rising during periods of non-dispensing and non-mixing allowing localized melting of the ice followed by refreezing. Additionally, the weight of the ice itself can cause localized melting also followed by refreezing. Further, continued mixing, as discussed above, can warm the ice, providing conditions which can lead to later clumping and can also degrade the ice quality through breakage.
The ice quality problem is exacerbated by current control systems operating in a manner such that when the low ice level is attained, the ice maker is activated and makes ice until the high level sensor turns off the ice maker. No accommodation is provided with such a control method to accommodate fluctuating ice demand during extended operating periods. Lack of ice and poor quality ice presents consumer acceptance problems.
Ice makers are many times part of vending machines that are on service routes. Should an ice maker become non-functional, e.g., because of ice clumping, it may be several days between visits by a service person to remedy the situation. A vending machine may then be out of service for extended periods of time causing consumer inconvenience.
The apparatus of the present invention includes a control system that is operable to commence ice making upon two or more operating conditions being met with one of the operating conditions being a low ice level in the hopper. The use of two or more operating conditions for control of ice making accommodates fluctuating ice demand and thereby improves operation and ice quality.